The move is significant, because if the group buys more than a 29 per cent shareholding it has to clarify its position on a takeover of the UK's third-largest supermarket.
Delta Two has bought 123 million Sainsbury's shares at 595p a share - an investment of£732 million. However, some analysts are unclear about why the Qataris are purchasing such large volumes of Sainsbury's shares. Seymour Pierce analyst Richard Ratner said: 'We are not certain what they see in this, other than trying to get the company to run itself in the listed arena as if it were a private equity play by putting the property into a REIT [real estate investment trust].'
Sainsbury's board rejected a bid by the CVC-led private equity consortium in April, which was believed to have been made at 582p.
Ratner said: 'If this [increased stake] is the prelude to a bid, one must remember that a 582p indicative offer has already been turned down by the family. At that level, the IRR [investment rate of return] was about 15 per cent - don't forget the pension fund. We cannot see, unless one lets vanity beat sanity, what higher figure would make sense.'